Set up languagedepot namespace in task setup

[rmunn]

This will avoid Skaffold deleting the languagedepot namespace when you run skaffold delete, so it doesn't have to be re-created each time.

The change to the ingress-deployment.yaml file is necessary because Kustomize was changing the ingress-nginx namespaces in there to languagedepot anyway, and therefore Skaffold was still deleting the languagedepot namespace when running skaffold delete because it was being created by ingress-deployment.yaml. Now that ingress-deployment.yaml uses the languagedepot namespace instead, and assumes it already exists, running skaffold delete; task up goes a lot faster.

Fixes #605.

[rmunn]

There's one thing that's still slow about running skaffold delete; task up, which is redownloading the large .zip files from Google Drive. I tried to fix that in #758, but discovered that it's just not possible (AFAICT) to get a file from your dev machine into a Kubernetes volume running under Docker Desktop. If anyone knows how to do that, please let me know.